Dual Active Bridge Topology Research Articles

Innovative heat sink design for enhanced cooling efficiency in Dual Active Bridge (DAB) topology

Abstract After in-depth research and analysis, aiming at the heat generation mechanism and limitations of the current heat dissipation method, this paper proposes an innovative heat dissipation design scheme. By optimizing the structural design of the heat sink, the heat dissipation surface area is increased, thus achieving more efficient heat emission and maintaining the optimal operating temperature of the equipment. Experimental data show that this new heat dissipation design significantly improves the cooling efficiency, an increase of about 60%, and provides support for the performance improvement of high-power power products, which brings a reliable and efficient cooling solution for related industries.

Ripple current control for single phase-shift dual active bridge converters

Nowadays, the need for isolated bidirectional DC/DC converters is growing. In these types of equipment, the dual active bridge topology is widespread, where mostly the trans- former leakage inductance value determines its dynamic behavior. Voltage imbalance between the primary and secondary side results in unwanted excessive transformer peak current if the leakage in- ductance is low, thus limiting the load transient response of the converter. In this paper, a ripple current control method is pre- sented, which reduces the transformer peak current to its minimal level, furthermore, allows the magnetizing current components to be distributed between the primary and secondary sides in an ar- bitrary proportion. The proposed control was tested in HIL sim- ulation and on a real 360kW dual active bridge converter. Based on the results the current stress on semiconductors and DC capac- itors were reduced while the utilization and the efficiency of the converter were increased.

Analysis of dual active bridge-based on-board battery charger for electric and hybrid vehicles

This paper presents an in-depth analysis of a Gallium Nitride (GaN) Dual Active Bridge (DAB)-based on-board battery charger for electric and hybrid vehicles. It focuses on the superior efficiency and reliability of GaN-based power electronics over traditional Silicon-based systems. The study explores the implementation of the DAB topology, recognized for its bidirectional power flow and high efficiency, in enhancing vehicle charging infrastructure. Efficiency analysis, switching behavior and losses are thoroughly examined. Simulation results in PSIM software validate the theoretical predictions, showing significant improvements in operational flexibility and energy efficiency.

AI-Based Design With Data Trimming for Hybrid Phase Shift Modulation for Minimum-Current-Stress Dual Active Bridge Converter

Dual active bridge (DAB) topology has been recognized as the key circuit for the next generation of high-frequency-link power conversion systems. In order to realize desired operating performance, DAB modulation strategies need to be selected carefully. Different modulation strategies have been considered and combined into a hybrid one, which is able to fully optimize performance. However, to develop a hybrid modulation strategy, the conventional methods including harmonic model and piecewise model have difficulty in balancing modeling accuracy and manpower burden. Although recent data-driven modulation approaches can automate the design process, the accuracy of data-driven models decreases nontrivially with the existence of outliers and without sufficient data. Hence, to alleviate human-dependence and improve modeling accuracy, this paper proposes an AI-based design with data trimming (AI-DT) for hybrid phase shift modulation. Two two-degree-of-freedom modulation strategies are considered for the sake of optimal current stress performance. AI-DT firstly adopts the one-class support vector machine (SVM) to exclude outliers. Second, the state-of-the-art extreme gradient boosting (XGBoost), which is insensitive to training data size, is adopted to build data-driven current stress models for the DAB converter. After that, differential evolution (DE) algorithm helps to choose modulation strategy and optimize modulation parameters for optimal current stress. Generally, the proposed AI-DT is developed in an automated fashion, which largely relieves manual computational complexity while exhibiting satisfactory modulation accuracy. The effectiveness of the proposed AI-DT approach has been experimentally verified with a 1kW hardware prototype, realizing optimal current stress under full operating conditions with more than 96.5% as peak efficiency.

Hybrid multimodule DC–DC converters accelerated by wide bandgap devices for electric vehicle systems

In response to the growing demand for fast-charging electric vehicles (EVs), this study presents a novel hybrid multimodule DC–DC converter based on the dual-active bridge (DAB) topology. The converter comprises eight modules divided into two groups: four Insulated-Gate Bipolar Transistor (IGBT) modules and four Metal–Semiconductor Field-Effect Transistor (MESFET) modules. The former handles high power with a low switching frequency, while the latter caters to lower power with a high switching frequency. This configuration leverages the strengths of both types of semiconductors, enhancing the converter’s power efficiency and density. To investigate the converter’s performance, a small-signal model is developed, alongside a control strategy to ensure uniform power sharing among the modules. The model is evaluated through simulation using MATLAB, which confirms the uniformity of the charging current provided to EV batteries. The results show an impressive power efficiency of 99.25% and a power density of 10.99 kW/L, achieved through the utilization of fast-switching MESFETs and the DAB topology. This research suggests that the hybrid multimodule DC–DC converter is a promising solution for fast-charging EVs, providing high efficiency, power density, and switching speed. Future studies could explore the incorporation of advanced wide bandgap devices to handle even larger power fractions.

Comparative analysis of three‐phase dual active bridge converter with different transformer topology and modern universal control for DC microgrids

AbstractThe presented work discusses issues related to the use of modern multiphase topologies of Dual Active Bridge (DAB)‐type converters. Converters of this type are widely used in most DC microgrid applications. The introduction emphasizes a comparative analysis between single‐phase and multi‐phase DAB topologies within high‐power DC microgrids, delving into their respective advantages, drawbacks, design procedures, and considerations based on the latest knowledge. The publication explores the comparison and selection of viable topologies for deployment in high‐power and high‐efficiency DC microgrids. The unified method of controlling 1‐phase and multi‐phase DAB converters was proposed in this design, simplifying the issues of DC microgrid control. All topologies were tested on the same controller concept. The study performs laboratory investigation of DAB 1‐phase and 3‐phase: Star–Star, and Star–Delta topologies. Attention was paid to maintaining uniform operating conditions of the system, contrary to studies known from the literature, all tests were carried out on the same laboratory stand and the same magnetic components in different configurations. Analytical and laboratory analyses of the Zero Voltage Switching (ZVS) region were performed, accounting for non‐linear phenomena. Based on these findings, an assessment of the system's performance in soft switching was carried out. The presented results were implemented in a simulation model and subsequently validated through tests on a constructed laboratory setup to ensure the proper operation of the system. This work meticulously presents and discusses variations in efficiency, dynamic response, phase current harmonic distribution, phase shift distribution, ZVS switching region, and more among the examined topologies. To ensure a fair comparison, the converter configuration for both simulation and laboratory models utilized identical components across all configurations.

Performance analysis of GaN based dual active bridge converter for electric vehicle charging application

<p><span>The research work proposes a Gallium Nitride (GaN) based dual active bridge (DAB) converter for electric vehicle (EV) charging applications. The wide bandgap semiconductor device, GaN is implemented in the DAB topology of an Isolated Bidirectional DC-DC converter (IBDC). GaN-based DC-DC converters lead to higher efficiency, smaller size, faster charging, and reduced heat generation improving the overall performance of the EV charging system. The performance characteristics of GaN based DAB converter is analyzed both in simulation and hardware for EV charging application. The same analysis is extended to a Si based DAB converter and comparative results are presented. A 14.25 kW GaN based DAB and <br /> 10.5 kW Si based DAB is designed and evaluated using LTspice XVII software and a scaled-down prototype of 0.612 kW GaN based DAB and 0.25 kW Si based DAB is presented for experimental validation. Result analysis under similar operating conditions indicated an improvement of 36% more output power transfer on the GaN based DAB over the traditional Si based DAB. The developed prototype showcased improved levels of power, voltage, and current under same operating conditions. The power transmission in the developed DAB based IBDC topology is controlled using the single-phase-shift (SPS) control strategy.</span></p>

Bidirectional Converter System in Dual Active Bridge Topology for a Hydrogen Tank

The paper presents a Dual Active Bridge (DAB) converter operating as an interface between the LiFePo4 battery and the fuel cell/hydrogen generator. The hydrogen tank can increase the stored energy of the battery system. Among the main requirements for a converter is the need to transfer power of up to 10 kW and operate with widely changing voltages on both sides of the converter. The design of the power electronic part and passive components of the converter is deeply discussed. Next, the influence of the wide voltage range on the operation of the converter is depicted, including its impact on power losses and current values. Different topological modifications for power loss reduction are presented and experimentally verified. Finally, a simple modification of the control system, giving the possibility of increasing efficiency, is briefly presented.

Enhanced Efficiency on ANPC-DAB through Adaptive Model Predictive Control

This work studies the DC-DC conversion stage in solid-state transformers (SST). The traditional two- or three-level dual active bridge (DAB) topology faces limitations in microgrid interconnection due to power and voltage limitations. For this reason, the use of multilevel topologies such as active neutral point clamped (ANPC) is a promising alternative. Additionally, the efficiency of the SSTs is a recurring concern, and reducing losses in the DC-DC stage is a subject to be studied. In this context, this work presents a new control technique based on an adaptive model- based predictive control (AMPC) to select the modulation technique of an ANPC-DAB DC-DC converter aimed at reducing losses and increasing efficiency. The single-phase shift (SPS), triangular, and trapezoidal modulation techniques are used according to the converter output power with the aim of maximizing the number of soft-switching points per cycle. The performance of the proposed control technique is demonstrated through real-time simulation and a reduced-scale experimental setup. The findings indicate the effectiveness of the AMPC control technique in mitigating voltage source perturbations. This technique has low output impedance and is robust to converter parameter variations. Prototyping tests revealed that, in steady-state, the AMPC significantly improves converter efficiency without compromising dynamic performance. Despite its advantages, the computational cost of AMPC is not significantly higher than that of traditional model predictive control (MPC), allowing for the allocation of time to other applications.

Soft-Switching Bidirectional Step-Up/Down Partial Power Converter With Reduced Components Stress

This paper introduces a step-up/down series partial power converter (S-PPC) based on isolated current-source dc-dc converter topology. The proposed S-PPC exploits the most important feature of the used current-source topology, such as the capability to operate with both voltage polarities in the series port to decrease its rated power. Other advantages include soft-switching in the entire operating range and low current stress of semiconductor components even at very low series voltage. In addition, the proposed S-PPC provides protection and soft-start capabilities due to the integration of a solid-state circuit breaker. The paper explains the operation principle of the proposed S-PPC and compares it to the closest known competing S-PPC based on the dual active bridge topology. An experimental prototype rated for 3.5 kW with maximum processed power of 600 W was built to confirm the converter operation principle and its features. Its experimental efficiency reaches 99.3 %. The proposed S-PPC also shows a good regulation capability at challenging operating points, like nearly zero series voltage.

Hybrid-Type Dual Active Bridge DC–DC Converter for Ultrawide Input-Voltage Range

This paper proposes a hybrid-type dual active bridge (H-DAB) topology and extended gain control (EG) method applied to the ultra-wide input-voltage range. The H-DAB is obtained by adding an auxiliary half-bridge to the conventional current-fed dual active bridge (CF-DAB) topology. The auxiliary half-bridge can assist the CF-DAB to achieve ZVS on the one hand, and further expand the voltage gain range on the other. The proposed extended gain control (EG) expands the input voltage range of ZVS for all switches by calculating the optimal intermediate bus voltage. In addition, the backflow power has also been drastically reduced. The proposed piecewise control strategy simplifies the complexity of control. The proposed topology and the control method are verified by the experimental results of a 500 W prototype. The input voltage range is 27 – 240 V and the output voltage is 375 V. The experimental results proved that the proposed scheme achieves ZVS of all switches in a wide input voltage range and power range, and the efficiency is improved.

Review of Dual-Active-Bridge Converters With Topological Modifications

Dual active bridge (DAB) converters inherit favorite features including zero voltage switching (ZVS) capability, wide voltage range, and natural bidirectional power flow. Facing different applications and high market requirements, conventional DAB topologies with various modulations are gradually inadequate, so topological modifications are emerged in literature to deal with these situations. Based on their characteristics of these modified DAB topologies, this paper provides a comprehensive review and classification, and the methodology to modify DAB topologies is proposed. Firstly, basic cells including input/output types, active bridges, transformers, and auxiliary high-frequency networks are introduced. Next, by combining these cells flexibly, modified DAB converters are derived, and they are classified in terms of structural characteristics and discussed in detail. Finally, the characteristics, merits, and demerits of the modified DAB converters are concluded. Evolvement history, future trends, and derivation of new topologies are also analyzed. This paper aims to present a clear picture of the general law and framework of the modified DAB topologies and give the inspiration to derive new DAB topologies to address specific requirements.

Hybrid-Type DAB Converter With DC Blocking Capacitor for Ultrawide Input-Voltage Range

In this letter, a hybrid-type dual active bridge topology with dc blocking capacitor for ultra-wide input voltage is proposed. The proposed topology can expand the gain range by introducing voltage offset across the dc blocking capacitor, and has the ability to operate in single-stage or two-stage mode. The control strategy is also designed, which adopts the minimum resistive loss under the premise of soft switching as the optimization object to derive the operating boundary of the optimal modes. The proposed methodology avoids the additional loss caused by the increased devices of the traditional two-stage converters, and also avoids the efficiency dip of traditional converters with dc blocking capacitor at non-optimal voltage matching points. The performance of the proposed scheme is verified by experimental results.

Multiple Open-Circuit Fault Detection and Isolation Using Universal Low-Cost Diagnosis Circuits for Reconfigurable Dual-Active-Bridge Converters

Compared with single-switch open-circuit faults (SOCFs), multiple switches open-circuit faults (MOCFs) of power electronic devices (PEDs) due to high voltage or current stress, false triggering, and manufacturing tolerance have become more challenging. To address this issue, a reconfigurable dual-active-bridge (R-DAB) converter is presented with a fast, accurate, robust, and low-cost fault detection (FD) and fault isolation (FI) scheme to accommodate both SOCFs and MOCFs. Compared with the standard dual active bridge (DAB) topology, the proposed R-DAB will utilize a center-tapped high-frequency transformer and two symmetrical auxiliary inductors, where inherent half-bridge conduction branches are capable of maintaining uninterrupted operations. The proposed FD and FI scheme is straightforward and universal since only the center-tap current in the primary and secondary bridge is monitored as the universal fault signature. Moreover, a simple and low-cost fault diagnostic circuit was designed, which can detect and isolate various open circuit faults (OCFs) of PEDs under varying input and output conditions, without using expensive voltage and current sensors. This sensorless fault diagnosis technique can achieve the fastest fault detection and isolation speed reported so far, which is within a couple of \boldmath <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mu s$</tex-math></inline-formula> for various OCFs. Experimental results were acquired from an R-DAB prototype under various OCFs to validate the effectiveness of the proposed technique.

A Quasi-Two-Stage Isolated Bidirectional Buck-DAB Converter for Wide Input Voltage Range

In this article, a quasi-two-stage buck-DAB (QBDAB) converter is proposed for improving the performance of the conventional dual active bridge (DAB) solution under a wide voltage range. For the proposed QBDAB converter, the DAB can always work under voltage matching conditions for wide voltage range applications, and the gain is adjusted through the added front-end circuit. The front-end circuit is similar to a buck converter, while only part of the transmission power flows through the circuit, which could also reduce the burden of achieving ZVS of the front-end circuit. Therefore, compared with the traditional two-stage buck-DAB converter solution, the related loss for the buck circuit can be reduced. The working principle, power transfer characteristics, and full load range ZVS design are analyzed deeply in this article. A detailed comparison of the QBDAB and other related combined buck+DAB topologies is also presented. Finally, the effectiveness of the proposed QBDAB is verified through experimental results from a 1kW prototype.

Systematic Review on Phase-Shift Optimization Strategies of Dual Active Bridge based DC-DC Converter

Bidirectional DC-DC converters (BDC) between high and low voltage buses are the most promising in latest research for their use cases in micro-grids. Specifically, the dual active bridge (DAB) topology of BDC has vast number of applications and its ability to transmit power in both directions makes it effective for utilities in consumer-prosumer setup. In recent years, a substantial amount of research has been conducted to eliminate one of the crucial drawbacks of DABs which is the mitigation of DC-Bias current resulting from practical limitations of switches. DC-Bias current is the leading cause of switch stress resulting in reduced converter reliability and efficiency. Numerous strategies have been devised to overcome this issue which includes methods like flux suppression, dynamic optimization, transient control, and piecewise linear transient phase shift optimization. In each of these categories several studies devised various techniques to increase operation efficiency, the dynamic response optimization (including model predictive controls and ANNs) can also be seen in recent research trends. This state-of-the-art systematic review is conducted on the recent developments in phase shift optimization techniques developed to increase the overall efficiency of isolated DABs. Considering it as a wide research discipline, the intervention criteria of searching the relevant primary studies is chosen to be strict. Some systematic reviews accommodate all the recent studies of this area, this review particularly is conducted to enhance the view only towards the phase shift-based optimization strategies and provide boarder insights of DAB optimization to researchers and engineers. It was seen that other than 3 basic phase shift techniques (SPS, DPS, TPS), studies with modified versions enhance the efficiency of DAB by mitigating the DB current.

A New Fault-Tolerant Scheme for Switch Failures in Dual Active Bridge DC-DC Converter

The dual active bridge (DAB) dc-dc converter is widely investigated for applications such as solid-state transformers (SSTs), battery energy storage systems, and electric vehicle (EV) chargers. Failures in active devices of the DAB can cause reduced terminal voltages or uncontrollable currents eventually leading to converter disconnection. The above-mentioned consequences cannot be corrected by disabling the complementary switches of the faulty leg or reconfiguring the full-bridge (FB) DAB to a half-bridge (HB) DAB topology. In this article, a new fault-tolerant (FT) approach is proposed that works for both short-circuit (SC) or open-circuit (OC) failures in the active devices of the DAB dc-dc converter. Parallel combination of a fault-tolerant capacitor and a fast acting fuse, known as fault-tolerant unit, is connected in series with the primary as well as secondary of the transformer. Once the fault is detected, the output voltage is boosted to its pre-fault value through the incorporation of fault-tolerant capacitors along with variation in control parameters, ensuring the continuity of operation. The proposed post-fault reconfiguration scheme is validated experimentally using a 1 kW, 250 V DAB prototype.

Adaptive Modulation of Resonant DAB Converters for Wide Range ZVS Operation With Minimum Reactive Circulating Power

Resonant mode dual active bridge (DAB) bidirectional dc–dc converters using either an inductive–capacitive–inductive ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCL</i> ) or a capacitive–inductive–capacitive ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CLC</i> ) ac-port network offer several performance benefits compared to more conventional nonresonant filter DAB topologies. This includes a reduction in the circulating power between the two bridges, which consequently enables the conduction loss to be minimized and the physical converter volume to be reduced. However, these gains also require that soft-switching is maintained, which is very challenging to achieve across all operating conditions, particularly at light loads. This article investigates the zero-voltage-switching (ZVS) capability of resonant mode DAB converters, applying Fourier analysis to the converter modulation patterns to quantify the ZVS boundaries analytically. The resulting analytic formulations also quantify the DAB real and reactive power flows, which subsequently enables the identification of modulation conditions that improve the converter's soft-switching and reactive circulating power flow behavior. The analysis is verified using detailed time-domain PSIM simulations matched to experimental DAB converters equipped with both <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCL</i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CLC</i> filters.

Adaptive Model Predictive Control for DAB Converter Switching Losses Reduction

The solid-state transformer is the enabling technology for the future of electric power systems. The increasing relevance of this equipment demands higher standards for efficiency and losses reduction. The dual active bridge (DAB) topology is the most usual DC-DC converter used in the solid-state transformer, and is responsible for part of its switching losses. The traditional phase-shift modulation used on DAB converters presents significant switching losses during the operation with reduced loads. The alternative Triangular and Trapezoidal Modulations have been proposed in recent literature; however, there are limitations on the maximum power these techniques can deal with. This paper presents an adaptive model predictive control to select among these three techniques, according to the converter model, the one that minimizes the switching losses and allows the current demanded by the load. Moreover, an alternative cost function is proposed, including the output voltage and current. Through real-time simulation, using a 1000 V/600 V 12 kW DAB converter, it is shown that the proposed control is able to reduce the losses on the converter. Furthermore, the proposed control presents fast and accurate response, and precise transition between the modulation techniques.

Optimized Modulation Strategy of NH3L-DAB Converter to Minimize RMS Current for Wide Voltage Range Applications

Dual active bridge (DAB) converter is one of the most popular bidirectional isolated dc/dc converters. Comparing with the two-level DAB converter, the multilevel DAB topologies take advantages of providing more control degrees of freedom to enhance the control flexibility. Therefore, these topologies are promising alternatives for wide voltage range applications. This article proposed an optimizing modulation strategy for neutral-point-clamped hybrid three-level dual active bridge (NH3L-DAB) converter to minimize the rms value of inductor current and the conduction losses. First, the basic operating principle of NH3L-DAB is analyzed comprehensively in the article. Afterward, the concept of global optimal condition is employed to derive the optimal modulation, and the corresponding analytical expressions of the control coordinates for rms current minimization are derived. By applying the optimal modulation strategy, NH3L-DAB facilitates to break the performance barriers of the prior-of-art of two-level DAB converter when the voltage transmission ratio has large variation. Finally, a bidirectional prototype with 200–450 V input and 20–28.8 V output is built to demonstrate the superior performance of the proposed optimal modulation strategy, and the detailed explanation of the experimental results is given as well.